Processing lines for articles such as fruit often require different quality articles to be separated. This is an important commercial function, which may be used for example, to distinguish between fruit destined for export and fruit destined for the local market. Manually grading articles is costly, slow and prone to inaccuracies. Thus, automated methods and apparatus for grading articles have been developed. Known sorters can grade and sort produce by weight, color, blemish, dimensions, shape, density, internal taste/quality etc.
The use of one or more video cameras is one known method of automatically sensing characteristics of articles. For example, the method and apparatus described in U.S. Pat. No. 4,825,068, the disclosure of which is incorporated herein by reference, uses a video camera in conjunction with mirrors to obtain a picture of each article as it travels past the line of sight of the mirrors. The mirrors enable a larger portion of the article, which is typically generally spherically shaped, to be simultaneously viewed by the camera.
Article carriers are used to transport articles such as fruit through various measurement stages for grading purposes and to eject fruit at a required location dependent on the result of the grading process. Such article carriers usually include an endless circuit of carriers or cups on a conveyor chain with the cup situated to unload fruit at one of a plurality of stations. There is also often a requirement to carry large numbers of incoming fruit using a plurality of parallel carriers. Typically such article carrier apparatus having multiple conveyor chains or belts are arranged to receive individual fruit articles into respective cups, the fruit being delivered on an adjacent infeed shelf.
The infeed shelf receives fruit and is typically inclined downwardly towards the plurality of article carriers, and may narrow in order to concentrate received fruit towards the article carriers. Some infeed shelves incorporate diverters which are typically blunt protrusions extending perpendicularly from the infeed shelve and angled to guide the fruit articles towards the incoming cups of the article conveyor chain. The diverters may also be used to balance the numbers of fruit directed to each article carrier to ensure high capacity carriage on each of the article carriers, for example, by ensuring that sufficient numbers of fruit articles are delivered to the article carriers at the outer ends of the parallel article carriers. The diverters are typically fixed and may be integral with the infeed shelf, however manual alignment or angling of the diverters may be provided in some infeed shelves.
Throughout this specification, any reference to items of prior art is in no way to be deemed as an admission that such prior art constitutes part of the common general knowledge.